Tower Bridge

Justin Tallis / AFP/Getty Images

The Tower Bridge serves as a backdrop as a 62-gun salute is unleashed from the Tower of London in honor of the arrival of the new prince -- 21 because it is a royal birth, 20 because the tower is a royal palace and 21 for the city of London, according to the BBC.

The Tower Bridge serves as a backdrop as a 62-gun salute is unleashed from the Tower of London in honor of the arrival of the new prince -- 21 because it is a royal birth, 20 because the tower is a royal palace and 21 for the city of London, according to the BBC. (Justin Tallis / AFP/Getty Images)

The Tower Bridge serves as a backdrop as a 62-gun salute is unleashed from the Tower of London in honor of the arrival of the new prince -- 21 because it is a royal birth, 20 because the tower is a royal palace and 21 for the city of London, according to the BBC.